Method and apparatus for high-speed processing of financial market depth data

ABSTRACT

A variety of embodiments for hardware-accelerating the processing of financial market depth data are disclosed. A coprocessor, which may be resident in a ticker plant, can be configured to update order books based on financial market depth data at extremely low latency. Such a coprocessor can also be configured to generate a quote event in response to a limit order event being determined to modify the top of an order book.

CROSS-REFERENCE AND PRIORITY CLAIM TO RELATED PATENT APPLICATIONS

This application is a divisional of International Patent Application No.PCT/US2009/067935, filed Dec. 14, 2009, and designating the U.S., whichclaims priority to U.S. patent application 61/122,673, filed Dec. 15,2008, entitled “Method and Apparatus for High-Speed Processing ofFinancial Market Depth Data”, the entire disclosures of both of whichare incorporated herein by reference.

This application is related to (1) U.S. patent application Ser. No.12/013,302, filed Jan. 11, 2008, entitled “Method and System for LowLatency Basket Calculation”, published as U.S. Patent ApplicationPublication 2009/0182683, (2) U.S. patent application Ser. No.11/765,306, filed Jun. 19, 2007, entitled “High Speed Processing ofFinancial Information Using FPGA Devices”, published as U.S. PatentApplication Publication 2008/0243675, (3) U.S. patent application Ser.No. 11/760,211, filed Jun. 8, 2007, entitled “Method and System for HighSpeed Options Pricing”, published as U.S. Patent Application Publication2007/0294157, and (4) U.S. patent application Ser. No. 11/561,615, filedNov. 20, 2006, entitled “Method and Apparatus for Processing FinancialInformation at Hardware Speeds Using FPGA Devices”, published as U.S.Patent Application Publication 2007/0078837, the entire disclosures ofeach of which are incorporated herein by reference.

TERMINOLOGY

The following paragraphs provide several definitions for various termsused herein. These paragraphs also provide background informationrelating to these terms.

Financial Instrument: As used herein, a “financial instrument” refers toa contract representing an equity ownership, debt, or credit, typicallyin relation to a corporate or governmental entity, wherein the contractis saleable. Examples of financial instruments include stocks, bonds,options, commodities, currency traded on currency markets, etc. butwould not include cash or checks in the sense of how those items areused outside the financial trading markets (i.e., the purchase ofgroceries at a grocery store using cash or check would not be covered bythe term “financial instrument” as used herein; similarly, thewithdrawal of $100 in cash from an Automatic Teller Machine using adebit card would not be covered by the term “financial instrument” asused herein).

Financial Market Data: As used herein, the term “financial market data”refers to data contained in or derived from a series of messages thatindividually represent a new offer to buy or sell a financialinstrument, an indication of a completed sale of a financial instrument,notifications of corrections to previously-reported sales of a financialinstrument, administrative messages related to such transactions, andthe like. Feeds of messages which contain financial market data areavailable from a number of sources and exist in a variety of feedtypes—for example, Level 1 feeds and Level 2 feeds as discussed herein.

Basket: As used herein, the term “basket” refers to a collectioncomprising a plurality of elements, each element having one or morevalues. The collection may be assigned one or more Net Values (NVs),wherein a NV is derived from the values of the plurality of elements inthe collection. For example, a basket may be a collection of data pointsfrom various scientific experiments. Each data point may have associatedvalues such as size, mass, etc. One may derive a size NV by computing aweighted sum of the sizes, a mass NV by computing a weighted sum of themasses, etc. Another example of a basket would be a collection offinancial instruments, as explained below.

Financial Instrument Basket: As used herein, the term “financialinstrument basket” refers to a basket whose elements comprise financialinstruments. The financial instrument basket may be assigned one or moreNet Asset Values (NAVs), wherein a NAV is derived from the values of theelements in the basket. Examples of financial instruments that may beincluded in baskets are securities (stocks), bonds, options, mutualfunds, exchange-traded funds, etc. Financial instrument baskets mayrepresent standard indexes, exchange-traded funds (ETFs), mutual funds,personal portfolios, etc. One may derive a last sale NAV by computing aweighted sum of the last sale prices for each of the financialinstruments in the basket, a bid NAV by computing a weighted sum of thecurrent best bid prices for each of the financial instruments in thebasket, etc.

GPP: As used herein, the term “general-purpose processor” (or GPP)refers to a hardware device having a fixed form and whose functionalityis variable, wherein this variable functionality is defined by fetchinginstructions and executing those instructions, of which a conventionalcentral processing unit (CPU) is a common example. Exemplary embodimentsof GPPs include an Intel Xeon processor and an AMD Opteron processor.

Reconfigurable Logic: As used herein, the term “reconfigurable logic”refers to any logic technology whose form and function can besignificantly altered (i.e., reconfigured) in the fieldpost-manufacture. This is to be contrasted with a GPP, whose functioncan change post-manufacture, but whose form is fixed at manufacture.

Software: As used herein, the term “software” refers to data processingfunctionality that is deployed on a GPP or other processing devices,wherein software cannot be used to change or define the form of thedevice on which it is loaded.

Firmware: As used herein, the term “firmware” refers to data processingfunctionality that is deployed on reconfigurable logic or otherprocessing devices, wherein firmware may be used to change or define theform of the device on which it is loaded.

Coprocessor: As used herein, the term “coprocessor” refers to acomputational engine designed to operate in conjunction with othercomponents in a computational system having a main processor (whereinthe main processor itself may comprise multiple processors such as in amulti-core processor architecture). Typically, a coprocessor isoptimized to perform a specific set of tasks and is used to offloadtasks from a main processor (which is typically a GPP) in order tooptimize system performance. The scope of tasks performed by acoprocessor may be fixed or variable, depending on the architecture ofthe coprocessor. Examples of fixed coprocessor architectures includeGraphics Processor Units which perform a broad spectrum of tasks andfloating point numeric coprocessors which perform a relatively narrowset of tasks. Examples of reconfigurable coprocessor architecturesinclude reconfigurable logic devices such as Field Programmable GateArrays (FPGAs) which may be reconfigured to implement a wide variety offixed or programmable computational engines. The functionality of acoprocessor may be defined via software and/or firmware.

Hardware Acceleration: As used herein, the term “hardware acceleration”refers to the use of software and/or firmware implemented on acoprocessor for offloading one or more processing tasks from a mainprocessor to decrease processing latency for those tasks relative to themain processor.

Bus: As used herein, the term “bus” refers to a logical bus whichencompasses any physical interconnect for which devices and locationsare accessed by an address. Examples of buses that could be used in thepractice of the present invention include, but are not limited to thePCI family of buses (e.g., PCI-X and PCI-Express) and HyperTransportbuses.

Pipelining: As used herein, the terms “pipeline”, “pipelined sequence”,or “chain” refer to an arrangement of application modules wherein theoutput of one application module is connected to the input of the nextapplication module in the sequence. This pipelining arrangement allowseach application module to independently operate on any data it receivesduring a given clock cycle and then pass its output to the nextdownstream application module in the sequence during another clockcycle.

BACKGROUND AND SUMMARY OF THE INVENTION

The process of trading financial instruments may be viewed broadly asproceeding through a cycle as shown in FIG. 1. At the top of the cycleis the exchange which is responsible for matching up offers to buy andsell financial instruments. Exchanges disseminate market information,such as the appearance of new buy/sell offers and trade transactions, asstreams of events known as market data feeds. Trading firms receivemarket data from the various exchanges upon which they trade. Note thatmany traders manage diverse portfolios of instruments requiring them tomonitor the state of multiple exchanges. Utilizing the data receivedfrom the exchange feeds, trading systems make trading decisions andissue buy/sell orders to the financial exchanges. Orders flow into theexchange where they are inserted into a sorted “book” of orders,triggering the publication of one or more events on the market datafeeds.

Exchanges keep a sorted listing of limit orders for each financialinstrument, known as an order book. As used herein, a “limit order”refers to an offer to buy or sell a specified number of shares of agiven financial instrument at a specified price. Limit orders can besorted based on price, size, and time according to exchange-specificrules. Many exchanges publish market data feeds that disseminate orderbook updates as order add, modify, and delete events. These feeds belongto a class of feeds known as level 2 data feeds. It should be understoodthat each exchange may be a little different as to when data ispublished on the feed and how much normalization the exchange performswhen publishing events on the feed, although it is fair to expect thatthe amount of normalization in the level 2 feed is minimal relative to alevel 1 feed. These feeds typically utilize one of two standard datamodels: full order depth or price aggregated depth. As shown in FIG. 2(a), full order depth feeds contain events that allow recipients toconstruct order books that mirror the order books used by the exchangematching engines. This is useful for trading strategies that requireknowledge of the state of specific orders in the market.

As shown in FIG. 2( b), price aggregated depth feeds contain events thatallow recipients to construct order books that report the distributionof liquidity (available shares) over prices for a given financialinstrument.

Order book feeds are valuable to electronic trading as they provide whatis generally considered the fastest and deepest insight into marketdynamics. The current set of order book feeds includes feeds for orderbooks of equities, equity options, and commodities. Several exchangeshave announced plans to provide new order book feeds for derivativeinstruments such as equity options. Given its explosive growth over thepast several years, derivative instrument trading is responsible for thelion's share of current market data traffic. The Options Price ReportingAuthority (OPRA) feed is the most significant source of derivativesmarket data, and it belongs to the class of feeds known as “level 1”feeds. Level 1 feeds report quotes, trades, trade cancels andcorrections, and a variety of summary events. For a given financialinstrument, the highest buy price and lowest sell price comprise the“best bid and offer” (BBO) that are advertised as the quote. As anexchange's sorted order book listing changes due to order executions,modifications, or cancellations, the exchange publishes new quotes. Whenthe best bid and offer prices match in the exchange's order book, theexchange executes a trade and advertises the trade transaction on itslevel 1 market data feed. Note that some amount of processing isrequired prior to publishing a quote or trade event because of thelatency incurred by the publisher's computer system when processinglimit orders to build order books and identify whether trades or quotesshould be generated. Thus, level 1 data feeds from exchanges or otherproviders possess inherent latency relative to viewing “raw” orderevents on order book feeds. A feed of raw limit order data belongs to aclass of feeds known as “level 2” feeds.

In order to minimize total system latency, many electronic trading firmsingest market data feeds, including market data feeds of limit orders,directly into their own computer systems from the financial exchanges.While some loose standards are in place, most exchanges define uniqueprotocols for disseminating their market data. This allows the exchangesto modify the protocols as needed to adjust to changes in marketdynamics, regulatory controls, and the introduction of new assetclasses. The ticker plant resides at the head of the platform and isresponsible for the normalization, caching, filtering, and publishing ofmarket data messages. A ticker plant typically provides a subscribeinterface to a set of downstream trading applications. By normalizingdata from disparate exchanges and asset classes, the ticker plantprovides a consistent data model for trading applications. The subscribeinterface allows each trading application to construct a customnormalized data feed containing only the information it requires. Thisis accomplished by performing subscription-based filtering at the tickerplant.

In traditional market data platforms known to the inventors, the tickerplant may perform some normalization tasks on order book feeds, but thetask of constructing sorted and/or price-aggregated views of order booksis typically pushed to downstream components in the market dataplatform. The inventors believe that such a trading platformarchitecture increases processing latency and the number of discretesystems required to process order book feeds. As an improvement oversuch an arrangement, an embodiment of the invention disclosed hereinenables a ticker plant to perform order feed processing (e.g.,normalization, price-aggregation, sorting) in an accelerated andintegrated fashion, thereby increasing system throughput and decreasingprocessing latency. In an exemplary embodiment, the ticker plant employsa coprocessor that serves as an offload engine to accelerate thebuilding of order books. Financial market data received on a feed intothe ticket plant can be transferred on a streaming basis to thecoprocessor for high speed processing.

Thus, in accordance with an exemplary embodiment of the invention, theinventors disclose a method for generating an order book view fromfinancial market depth data, the method comprising: (1) maintaining adata structure representative of a plurality of order books for aplurality of financial instruments, and (2) hardware-accelerating aprocessing of a plurality of financial market depth data messages toupdate the order books within the data structure. Preferably thehardware-accelerating step is performed by a coprocessor within a tickerplant. The inventors also disclose a system for generating an order bookview from financial market depth data, the system comprising: (1) amemory for storing a data structure representative of a plurality oforder books for a plurality of financial instruments, and (2) acoprocessor configured to process of a plurality of financial marketdepth data messages to update the order books within the data structure.

Using these order books, the method and system can also produce views ofthose order books for ultimate delivery to interested subscribers. Theinventors define two general classes of book views that can be producedin accordance with various exemplary embodiments: stream views(unsorted, non-cached) and summary views (sorted, cached). Stream viewsprovide client applications with a normalized stream of updates forlimit orders or aggregated price-points for the specified regionalsymbol, composite symbol, or feed source (exchange). Summary viewsprovide client applications with multiple sorted views of the book,including composite views (a.k.a. “virtual order books”) that spanmultiple markets.

In an exemplary embodiment, stream views comprise a normalized stream ofupdates for limit orders or aggregated price-points for the specifiedregional symbol, composite symbol, or feed source (exchange). Followingthe creation of a stream subscription, a ticker plant can be configuredto provide a client application with a stream of normalized eventscontaining limit order or price point updates. As stream subscriptionsdo not provide sorting, it is expected that stream view data would beemployed by client applications that construct their own book views orjournals from the normalized event stream from one or more specifiedexchanges.

An example of a stream view that can be generated by various embodimentsis an order stream view. An order stream view comprises a stream ofnormalized limit order update events for one or more specified regionalsymbols. The normalized events comprise fields such as the type ofupdate (add, modify, delete), the order price, order size, exchangetimestamp, and order identifier (if provided by the exchange). Anotherexample of an order stream view is an order exchange stream view thatcomprises a stream of normalized limit order update events for one ormore specified exchanges or clusters of instruments within an exchange.The normalized events comprise fields such as the type of update (add,modify, delete), the order price, order size, exchange timestamp, andorder identifier (if provided by the exchange).

Another example of a stream view that can be generated by variousembodiments is a price stream view. A price stream view comprises astream of normalized price level update events for one or more specifiedregional symbols. The normalized events comprise fields such as the typeof update (add, modify, delete), the aggregated price, order volume atthe aggregated price, and the order count at the aggregated price.Another example of a price stream view is a price exchange stream view.A price exchange stream view comprises a stream of normalized pricelevel update events for one or more specified exchanges or clusters ofinstruments within an exchange. The normalized events comprise fieldssuch as the type of update (add, modify, delete), the aggregated price,order volume at the aggregated price, and order count at the aggregatedprice.

Another example of a stream view that can be generated by variousembodiments is an aggregate stream view. An aggregate stream viewcomprises a stream of normalized price level update events for one ormore specified composite symbols. The normalized events comprise fieldssuch as the type of update (add, modify, delete), the (virtual)aggregated price, (virtual) order volume at the aggregated price, and(virtual) order count at the aggregated price.

As explained in the above-referenced and incorporated U.S. PatentApplication Publication 2008/0243675, a regional symbol serves toidentify a financial instrument traded on a particular exchange while acomposite symbol serves to identify a financial instrument in theaggregate on all of the exchanges upon which it trades. It should beunderstood that embodiments of the invention disclosed herein may beconfigured to store both regional and composite records for the samefinancial instrument in situations where the financial instrument istraded on multiple exchanges.

Summary views provide liquidity insight, and the inventors believe it ishighly desirable to obtain such liquidity insight with ultra lowlatency. In accordance with an embodiment disclosed herein, byoffloading a significant amount of data processing from clientapplications to a ticker plant, the ticker plant frees up clientprocessing resources, thereby enabling those client resources toimplement more sophisticated trading applications that retain firstmover advantage.

An example of a summary view that can be generated by variousembodiments is an order summary view. An order summary view represents afirst-order liquidity view of the raw limit order data disseminated by asingle feed source. The inventors define an order summary view to be asorted listing comprising a plurality of individual limit orders for agiven financial instrument on a given exchange. The sort order ispreferably by price and then by time (or then by size for someexchanges). An example of an order summary view is shown in FIG. 3.

Another example of a summary view that can be generated by variousembodiments is a price summary view. A price summary view represents asecond-order liquidity view of the raw limit order data disseminated bya single feed source. The inventors define a price summary view to be asorted listing comprising a plurality of price levels for a givenfinancial instrument on a given exchange, wherein each price levelrepresents an aggregation of same-priced orders from that exchange. Theprice level timestamp in the summary view preferably reports thetimestamp of the most recent event at that price level from thatexchange. An example of a price summary view is shown in FIG. 4( a).Note that a price summary view produced by an embodiment disclosedherein may be limited to a user-specified number of price pointsstarting from the top of the book.

Another example of a summary view that can be generated by variousembodiments is a spliced price summary view. A spliced price summaryview represents a second-order, pan-market liquidity view of the rawlimit order data disseminated by multiple feed sources. The inventorsdefine a spliced price summary view to be a sorted listing comprising aplurality of price levels for a given financial instrument across allcontributing exchanges where each price level represents an aggregationof same-priced orders from a unique contributing exchange. The pricelevel timestamp in the spliced price summary view preferably reports thetimestamp of the most recent event at that price level for the specifiedexchange. An example of a spliced price summary view is shown in FIG. 4(b). Note that a spliced price summary view produced by an embodimentdisclosed herein may be limited to a user-specified number of pricepoints starting from the top of the book.

Another example of a summary view that can be generated by variousembodiments is an aggregate price summary view. An aggregate pricesummary view represents a third-order, pan-market liquidity view of theraw limit order data disseminated by multiple feed sources. Theinventors define an aggregate price summary view to be a sorted listingcomprising a plurality of price levels for a given financial instrumentwhere each price level represents an aggregation of same-priced ordersfrom all contributing exchanges. The price level timestamp in theaggregate price summary view preferably reports the timestamp of themost recent event at that price level from any contributing exchange. Anexample of an aggregate price summary view is shown in FIG. 4( c). Notethat an aggregate price summary view produced by an embodiment disclosedherein may be limited to a user-specified number of price pointsstarting from the top of the book.

The inventors further note that financial exchanges have continued toinnovate in order to compete and to provide more efficient markets. Oneexample of such innovation is the introduction of ephemeral regionalorders in several equity markets (e.g., FLASH orders on NASDAQ, BOLTorders on BATS) that provide regional market participants theopportunity to view specific orders prior to public advertisement.Another example of such innovation is implied liquidity in severalcommodity markets (e.g. CME, ICE) that allow market participants totrade against synthetic orders whose price is derived from otherderivative instruments. In order to capture and distinguish this type oforder or price level in an order book, the inventors define the conceptof attributes and apply this concept to the data structures employed byvarious embodiments disclosed herein. Each entry in an order book orprice book may have one or more attributes. Conceptually, attributes area vector of flags that may be associated with each order book or pricebook entry. By default, every order or aggregated price level is“explicit” and represents a limit order to buy or sell the associatedfinancial instrument entered by a market participant. In some equitymarkets, an order or price level may be flagged using variousembodiments disclosed herein with an attribute to indicate whether theorder or price level relates to an ephemeral regional order (ERO).Similarly, in some commodity markets, an order or price level may beflagged using various embodiments disclosed herein to indicate whetherthe order or price level relates to an implied liquidity.

By capturing such attributes in the data structures employed byexemplary embodiments, the inventors note that these attributes thusprovide another dimension to the types of book views that variousembodiments disclosed herein generate. For example, one commoditytrading application may wish to view a price aggregated book that omitsimplied liquidity, another commodity trading application may wish toview a price aggregated book with the explicit and implied price levelsshown independently (spliced view), while another commodity tradingapplication may wish to view a price aggregated book with explicit andimplied entries aggregated by price. These three examples ofattribute-based book views are shown in FIGS. 5, 6 and 7, respectively.

Thus, in accordance with an exemplary embodiment, the inventors disclosethe use of attribute filtering and price level merging to capture therange of options in producing book views for books that contain entrieswith attributes. Attribute filtering allows applications to specifywhich entries should be included and/or excluded from the book view.Price level merging allows applications to specify whether or notentries that share the same price but differing attributes should beaggregated into a single price level.

The inventors also disclose several embodiments wherein a coprocessorcan be used to enrich a stream of limit order events pertaining tofinancial instruments with order book data, both stream view order bookdata and summary view order book data, as disclosed herein.

These and other features and advantages of the present invention will bedescribed hereinafter to those having ordinary skill in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an exemplary process cycle for trading financialinstruments;

FIG. 2( a) depicts an exemplary limit order event and its relation to afull order depth book;

FIG. 2( b) depicts an exemplary limit order event and its relation to aprice aggregated depth order book;

FIG. 3 depicts exemplary bid and ask order summary views;

FIG. 4( a) depicts exemplary bid and ask price summary views;

FIG. 4( b) depicts exemplary bid and ask spliced price summary views;

FIG. 4( c) depicts exemplary bid and ask aggregate price summary views;

FIG. 5 depicts an exemplary price book view, with implied attributesfiltered out;

FIG. 6 depicts an exemplary price book view, including a splicedattribute view;

FIG. 7 depicts an exemplary price book view, including a price mergedattribute view;

FIGS. 8( a) and (b) depict examples of suitable platforms for processingmarket depth data;

FIGS. 9( a) and (b) depict exemplary printed circuit boards for use as acoprocessor;

FIG. 10 depicts an example of how a firmware pipeline can be deployedacross multiple reconfigurable logic devices;

FIGS. 11( a)-(c) depicts various embodiments of a processing module forprocessing limit order data;

FIGS. 12( a)-(c) depict various embodiments of a pipeline for generatingstream views of order books;

FIG. 13 depicts an exemplary embodiment of a compression function usedto generate a hash key for symbol mapping;

FIG. 14 depicts an exemplary embodiment of a hash function for symbolmapping;

FIG. 15 depicts an exemplary embodiment for generating a global exchangeidentifier (GEID) for symbol mapping;

FIG. 16 depicts an exemplary embodiment of a module configured to enrichlimit order events with normalization and price aggregation data;

FIG. 17 depicts an exemplary embodiment for storing and accessing limitorder records and price point records, wherein such records are storedin a shared memory;

FIG. 18 depicts another exemplary embodiment for storing and accessinglimit order records and price point records, wherein such records arepartitioned across multiple physical memories;

FIG. 19 depicts an exemplary limit order event;

FIG. 20 depicts an exemplary limit order record;

FIG. 21( a) depicts an exemplary regional price point record;

FIG. 21( b) depicts an exemplary composite price point record;

FIG. 22 depicts an exemplary enriched limit order event;

FIG. 23 depicts an exemplary architecture for an order normalization andprice aggregation (ONPA) module;

FIG. 24 depicts an exemplary embodiment where an API in a clientapplication is configured to produce a sorted view of an order book froma stream view of an order book provided by a ticker plant;

FIGS. 25( a)-(d) depict various embodiments of a pipeline for generatingsummary views of order books;

FIG. 26 depicts an example of a B+ tree;

FIG. 27 depicts an example of how a module can be configured to accesssorted order book data within a data structure;

FIG. 28 depicts an exemplary architecture for a sorted view update (SVU)module;

FIG. 29 depicts an exemplary pipeline that includes a value cache update(VCU) module operating on synthetic quote events created by an SVUmodule;

FIG. 30 depicts an exemplary pipeline that includes a basket calculationengine (BCE) module driven in part by synthetic quote events created byan SVU module; and

FIG. 31 depicts an exemplary ticker plant architecture in which apipeline configured to process financial market depth data can beemployed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Examples of suitable platforms for implementing exemplary embodiments ofthe invention are shown in FIGS. 8( a) and (b). FIG. 8( a) depicts asystem 800 employs a hardware-accelerated data processing capabilitythrough coprocessor 840 to process financial market depth data. Withinsystem 800, a coprocessor 840 is positioned to receive data that streamsinto the system 800 from a network 820 (via network interface 810). In apreferred embodiment, system 800 is employed to receive financial marketlimit order data and process financial market depth data. Network 820thus preferably comprises a network through which system 800 can accessa source for Level 2 financial data such as the exchanges themselves(e.g., NYSE, NASDAQ, etc.) or a third party provider (e.g., extranetproviders such as Savvis or BT Radians). Such incoming data preferablycomprises a series of financial market data messages, the messagesrepresenting events such as limit orders relating to financialinstruments. These messages can exist in any of a number of formats, asis known in the art.

The computer system defined by processor 812 and RAM 808 can be anycommodity computer system as would be understood by those havingordinary skill in the art. For example, the computer system may be anIntel Xeon system or an AMD Opteron system. Thus, processor 812, whichserves as the central or main processor for system 800, preferablycomprises a GPP.

In a preferred embodiment, the coprocessor 840 comprises areconfigurable logic device 802. Preferably, data streams into thereconfigurable logic device 802 by way of system bus 806, although otherdesign architectures are possible (see FIG. 9( b)). Preferably, thereconfigurable logic device 802 is a field programmable gate array(FPGA), although this need not be the case. System bus 806 can alsointerconnect the reconfigurable logic device 802 with the processor 812as well as RAM 808. In a preferred embodiment, system bus 806 may be aPCI-X bus or a PCI-Express bus, although this need not be the case.

The reconfigurable logic device 802 has firmware modules deployedthereon that define its functionality. The firmware socket module 804handles the data movement requirements (both command data and targetdata) into and out of the reconfigurable logic device, thereby providinga consistent application interface to the firmware application module(FAM) chain 850 that is also deployed on the reconfigurable logicdevice. The FAMs 850 i of the FAM chain 850 are configured to performspecified data processing operations on any data that streams throughthe chain 850 from the firmware socket module 804. Examples of FAMs thatcan be deployed on reconfigurable logic in accordance with a preferredembodiments of the present invention are described below.

The specific data processing operation that is performed by a FAM iscontrolled/parameterized by the command data that FAM receives from thefirmware socket module 804. This command data can be FAM-specific, andupon receipt of the command, the FAM will arrange itself to carry outthe data processing operation controlled by the received command. Forexample, within a FAM that is configured to perform an exact matchoperation between data and a key, the FAM's exact match operation can beparameterized to define the key(s) that the exact match operation willbe run against. In this way, a FAM that is configured to perform anexact match operation can be readily re-arranged to perform a differentexact match operation by simply loading new parameters for one or moredifferent keys in that FAM. As another example pertaining to baskets, acommand can be issued to the one or more FAMs that make up a basketcalculation engine to add/delete one or more financial instrumentsto/from the basket.

Once a FAM has been arranged to perform the data processing operationspecified by a received command, that FAM is ready to carry out itsspecified data processing operation on the data stream that it receivesfrom the firmware socket module. Thus, a FAM can be arranged through anappropriate command to process a specified stream of data in a specifiedmanner. Once the FAM has completed its data processing operation,another command can be sent to that FAM that will cause the FAM tore-arrange itself to alter the nature of the data processing operationperformed thereby. Not only will the FAM operate at hardware speeds(thereby providing a high throughput of data through the FAM), but theFAMs can also be flexibly reprogrammed to change the parameters of theirdata processing operations.

The FAM chain 850 preferably comprises a plurality of firmwareapplication modules (FAMs) 850 a, 850 b, . . . that are arranged in apipelined sequence. However, it should be noted that within the firmwarepipeline, one or more parallel paths of FAMs 850 i can be employed. Forexample, the firmware chain may comprise three FAMs arranged in a firstpipelined path (e.g., FAMs 850 a, 850 b, 850 c) and four FAMs arrangedin a second pipelined path (e.g., FAMs 850 d, 850 e, 850 f, and 850 g),wherein the first and second pipelined paths are parallel with eachother. Furthermore, the firmware pipeline can have one or more pathsbranch off from an existing pipeline path. A practitioner of the presentinvention can design an appropriate arrangement of FAMs for FAM chain850 based on the processing needs of a given application.

A communication path 830 connects the firmware socket module 804 withthe input of the first one of the pipelined FAMs 850 a. The input of thefirst FAM 850 a serves as the entry point into the FAM chain 850. Acommunication path 832 connects the output of the final one of thepipelined FAMs 850 m with the firmware socket module 804. The output ofthe final FAM 850 m serves as the exit point from the FAM chain 850.Both communication path 830 and communication path 832 are preferablymulti-bit paths.

The nature of the software and hardware/software interfaces used bysystem 800, particularly in connection with data flow into and out ofthe firmware socket module are described in greater detail in U.S.Patent Application Publication 2007/0174841, the entire disclosure ofwhich is incorporated herein by reference.

FIG. 8( b) depicts another exemplary embodiment for system 800. In theexample of FIG. 8( b), system 800 includes a data store 842 that is incommunication with bus 806 via disk controller 814. Thus, the data thatis streamed through the coprocessor 840 may also emanate from data store842. Data store 842 can be any data storage device/system, but it ispreferably some form of mass storage medium. For example, data store 842can be a magnetic storage device such as an array of Seagate disks.

FIG. 9( a) depicts a printed circuit board or card 900 that can beconnected to the PCI-X or PCI-e bus 806 of a commodity computer systemfor use as a coprocessor 840 in system 800 for any of the embodiments ofFIGS. 8( a)-(b). In the example of FIG. 9( a), the printed circuit boardincludes an FPGA 802 (such as a Xilinx Virtex 5 FPGA) that is incommunication with a memory device 902 and a PCI-X bus connector 904. Apreferred memory device 902 comprises SRAM and DRAM memory. A preferredPCI-X or PCI-e bus connector 904 is a standard card edge connector.

FIG. 9( b) depicts an alternate configuration for a printed circuitboard/card 900. In the example of FIG. 9( b), a bus 906 (such as a PCI-Xor PCI-e bus), one or more disk controllers 908, and a disk connector910 are also installed on the printed circuit board 900. Any commoditydisk interface technology can be supported, as is understood in the art.In this configuration, the firmware socket 804 also serves as a PCI-X toPCI-X bridge to provide the processor 812 with normal access to anydisk(s) connected via the private PCI-X bus 906. It should be noted thata network interface can be used in addition to or in place of the diskcontroller and disk connector shown in FIG. 9( b).

It is worth noting that in either the configuration of FIG. 9( a) or9(b), the firmware socket 804 can make memory 902 accessible to the bus806, which thereby makes memory 902 available for use by an OS kernel asthe buffers for transfers to the FAMs from a data source with access tobus. It is also worth noting that while a single FPGA 802 is shown onthe printed circuit boards of FIGS. 9( a) and (b), it should beunderstood that multiple FPGAs can be supported by either including morethan one FPGA on the printed circuit board 900 or by installing morethan one printed circuit board 900 in the system 800. FIG. 10 depicts anexample where numerous FAMs in a single pipeline are deployed acrossmultiple FPGAs.

FIGS. 11( a)-(c) depict examples of processing modules 1100 that can beemployed within coprocessor 840 to process limit order events. Theprocessing module 1100 of FIG. 11( a) is configured to generate a streamview of processed limit order data. The processing module 1100 of FIG.11( b) is configured to generate a summary view of processed limit orderdata, and the processing module 1100 of FIG. 11( c) is configured togenerate both a stream view and a summary view of processed limit orderdata.

In the exemplary embodiments of FIG. 12( a)-(c), a data processingmodule 1100 for generating a stream view of processed limit order datacan be realized via a pipeline 1200. In the example of FIG. 12( a), thepipeline comprises a message parsing (MP) module 1204 that receives rawmessages 1202. These messages 1202 comprise a stream of financial marketdata events, of which at least a plurality comprise limit order events.Downstream from the MP module 1204 is a symbol mapping (SM) module 1206,and downstream from the SM module 1206 is an Order Normalization andPrice Aggregation (ONPA) module 1208. The ONPA module 1208, as explainedbelow, is configured to generate the stream view of the limit order datacontained in limit order events.

The MP module 1204 is configured to parse the incoming stream of rawmessages 1202 into a plurality of parsed messages having data fieldsthat can be understood by downstream modules. Exemplary embodiments forsuch an MP module are described in the above-referenced and incorporatedU.S. Patent Application Publication 2008/0243675. Thus, the MP modulesis configured to process incoming raw messages 1202 to create limitorder events that can be understood by downstream modules.

The SM module 1206 resolves a unique symbol identifier for the basefinancial instrument and the associated market center for a receivedevent. Input events may contain a symbol field that uniquely identifiesthe base financial instrument. In this case, the symbol mapping stageperforms a one-to-one translation from the input symbol field to thesymbol identifier, which is preferably a minimally-sized binary tag thatprovides for efficient lookup of associated state information for thefinancial instrument. Thus, the SM module 1206 operates to map the knownsymbol for a financial instrument (or set of financial instruments) asdefined in the parsed message to a symbology that is internal to theplatform (e.g., mapping the symbol for IBM stock to an internal symbol“12345”). Preferably, the internal platform symbol identifier (ID) is aninteger in the range 0 to N−1, where N is the number of entries in asymbol index memory. Also, the symbol ID may formatted as a binary valueof size M=log₂(N) bits. The format of financial instrument symbols ininput exchange messages varies for different message feeds and financialinstrument types. Typically, the symbol is a variable-length ASCIIcharacter string. A symbology ID is an internal control field thatuniquely identifies the format of the symbol string in the message. Asshown in FIG. 13, a symbology ID is preferably assigned by a feedhandler and present in all incoming messages, as the symbol stringformat is typically shared by all messages on a given input feed.

An exemplary embodiment of the SM module 1206 maps each unique symbolcharacter string to a unique binary number of size M bits. In such anexemplary embodiment, the symbol mapping FAM performs a format-specificcompression of the symbol to generate a hash key of size K bits, where Kis the size of the entries in a symbol index memory. The symbology IDmay be used to lookup a Key Code that identifies the symbol compressiontechnique that should be used for the input symbol. Preferably, thesymbol mapping FAM compresses the symbol using format-specificcompression engines and selects the correct compressed symbol outputusing the key code. Also, the key code can be concatenated with thecompressed symbol to form the hash key. In doing so, each compressiontechnique is allocated a subset of the range of possible hash keys. Thisensures that hash keys will be unique, regardless of the compressiontechnique used to compress the symbol. An example is shown in FIG. 13wherein the ASCII symbol for a financial instrument is compressed inparallel by a plurality of different compression operations (e.g.,alpha-numeric ticker compression, ISIN compression, and commoditycompression). Compression techniques for different symbologies can beselected and/or devised on an ad hoc basis as desired by a practitioner.A practitioner is free to select a different compression operation asmay be appropriate for a given symbology. Based on the value of the keycode, the SM module will pass one of the concatenations of the key codeand compression results as the output from the multiplexer for use asthe hash key.

Alternatively, the format-specific compression engines may beimplemented in a programmable processor. The key code may then be usedto fetch a sequence of instructions that specify how the symbol shouldbe compressed.

Once the hash key is generated, the SM module 1206 maps the hash key toa unique address in a symbol index memory in the range 0 to N−1. Thesymbol index memory may be implemented in a memory “on-chip” (e.g.,within the reconfigurable logic device) or in “off-chip” high speedmemory devices such as SRAM and SDRAM that are accessible to thereconfigurable logic device. Preferably, this mapping is performed by ahash function. A hash function attempts to minimize the number ofprobes, or table lookups, to find the input hash key. In manyapplications, additional meta-data is associated with the hash key. Inan exemplary embodiment, the location of the hash key in the symbolindex memory is used as the unique internal Symbol ID for the financialinstrument.

FIG. 14 shows an exemplary embodiment of a hash function to perform thismapping that represents a novel combination of known hashing methods.The hash function of FIG. 14 uses near-perfect hashing to compute aprimary hash function, then uses open-addressing to resolve collisions.The hash function H(x) is described as follows:H(x)=(h1(x)+(i*h2(x)))mod Nh1(x)=A(x)⊕d(x)d(x)=T(B(x))h2(x)=C(x)

The operand x is the hash key generated by the previously describedcompression stage. The function h1(x) is the primary hash function. Thevalue i is the iteration count. The iteration count i is initialized tozero and incremented for each hash probe that results in a collision.For the first hash probe, hash function H(x)=h1(x), thus the primaryhash function determines the first hash probe. The preferred hashfunction disclosed herein attempts to maximize the probability that thehash key is located on the first hash probe. If the hash probe resultsin a collision, the hash key stored in the hash slot does not match hashkey x, the iteration count is incremented and combined with thesecondary hash function h2(x) to generate an offset from the first hashprobe location. The modulo N operation ensures that the final result iswithin the range 0 to N−1, where N is the size of the symbol indexmemory. The secondary hash function h2(x) is designed so that itsoutputs are prime relative to N. The process of incrementing i andrecomputing H(x) continues until the input hash key is located in thetable or an empty table slot is encountered. This technique of resolvingcollisions is known as open-addressing.

The primary hash function, h1(x), is computed as follows. Compute hashfunction B(x) where the result is in the range 0 to Q−1. Use the resultof the B(x) function to lookup a displacement vector d(x) in table Tcontaining Q displacement vectors. Preferably the size of thedisplacement vector d(x) in bits is equal to M. Compute hash functionA(x) where the result is M bits in size. Compute the bitwise exclusiveOR, ⊕, of A(x) and d(x). This is one example of near-perfect hashingwhere the displacement vector is used to resolve collisions among theset of hash keys that are known prior to the beginning of the querystream. Typically, this fits well with streaming financial data wherethe majority of the symbols for the instruments trading in a given dayis known. Methods for computing displacement table entries are known inthe art.

The secondary hash function, h2(x), is computed by computing a singlehash function C(x) where the result is always prime relative to N. Hashfunctions A(x), B(x), and C(x) may be selected from the body of knownhash functions with favorable randomization properties. Preferably, hashfunctions A(x), B(x), and C(x) are efficiently implemented in hardware.The set of H3 hash functions are good candidates. (See Krishnamurthy etal., “Biosequence Similarity Search on the Mercury System”, Proc. of theIEEE 15th Int'l Conf. on Application-Specific Systems, Architectures andProcessors, September 2004, pp. 365-375, the entire disclosure of whichis incorporated herein by reference).

Once the hash function H(x) produces an address whose entry is equal tothe input hash key, the address is passed on as the new Symbol ID to beused internally by the ticker plant to reference the financialinstrument. As shown in FIG. 14, the result of the hash key comparefunction may be used as a valid signal for the symbol ID output.

Hash keys are inserted in the table when an exchange message contains asymbol that was unknown at system initialization. Hash keys are removedfrom the table when a financial instrument is no longer traded.Alternatively, the symbol for the financial instrument may be removedfrom the set of known symbols and the hash table may be cleared,recomputed, and initialized. By doing so, the displacement table usedfor the near-perfect hash function of the primary hash may be optimized.Typically, financial markets have established trading hours that allowfor after-hours or overnight processing. The general procedures forinserting and deleting hash keys from a hash table where open-addressingis used to resolve collisions is well-known in the art.

In an exemplary embodiment, the SM module 1210 can also be configured tocompute a global exchange identifier (GEID) that maps the exchange codeand country code fields in the exchange message to an integer in therange 0 to G−1, as shown in FIG. 15. Similar to the symbol field forfinancial instruments, the exchange code and country code fieldsuniquely identify the source of the exchange message. Thus, the globalexchange identifier (GEID) preferably comprises a binary tag thatuniquely identifies a particular exchange for this the message isrelevant. The value of G should be selected such that it is larger thanthe total number of sources (financial exchanges) that will begenerating input messages for a given instance of the system. Hashingcould be used to map the country codes and exchange codes to the GEID.Alternatively, a “direct addressing” approach can be used to map countryand exchange codes to GEIDs. For example, the exchange code and countrycodes can each be represented by two character codes, where thecharacters are 8-bit upper-case ASCII alpha characters. These codes canthen be truncated to 5-bit characters in embodiment where only 26 uniquevalues of these codes are needed. For each code, these truncated valuesare concatenated to generate a 10-bit address that is used to lookup acompressed intermediate value in a stage 1 table. Then the compressedintermediate values for the exchange and country code can beconcatenated to generate an address for a stage 2 lookup. The result ofthe stage 2 lookup is the GEID. The size of the intermediate values andthe stage 2 address will depend on the number of unique countries andthe max number of exchanges in any one country, which can be adjusted asnew exchanges open in different countries.

The ONPA module 1208 then receives a stream of incoming limit orderevents 1600, as shown in FIG. 16. The ONPA module accesses a memory 1602that stores data structures which comprise the various order bookstracked by the system to determine (1) how to update the data structuresin view of the received limit order event, and (2) how to enrich thelimit order event in view of its relation to the tracked order books.The output from the ONPA module 1208 is an outgoing stream of enrichedlimit order events 1604.

FIG. 19 depicts an exemplary limit order event 1600. As exemplary datafields, the limit order event comprises a symbol field 1902 and GEIDfield 1904 (as mapped by the SM module 1206). The event may also includea reference number field 1906, typically assigned by the publisher ofthe event to identify a particular limit order. Additional data fieldsfor the event 1600 comprise a flag 1908 to identify whether the limitorder pertains to a bid or ask, a field 1910 to identify a price for thelimit order, a field 1912 to identify the size for the limit order(e.g., share count), and a timestamp field 1914. Furthermore, the event1600 preferably comprises one or more flags 1916 that identify whetherone or more attributes are applicable to the event. For example, asdiscussed above, the value of the attribute flag field 1916 can identifywhether the limit order pertains to an ephemeral regional order (e.g., aFLASH order on NASDAQ or a BOLT order on BATS) and whether the limitorder is implied. Lastly, the limit order event 1600 may comprise one ormore flags 1918 for identifying whether the limit order event is an addevent, modify event or delete event. Thus the add, modify, delete (AMD)flags field 1918 will enable an ONPA module 1208 to decide whether areceived limit order event represents a new limit order (the add flag),a modification to a pre-existing limit order (the modify flag), or adeletion of an pre-existing limit order (the delete flag).

It should be understood that many limit order events 1600 will not havethe same fields shown in the example of FIG. 19, whether there bedifferences in the number of fields and/or the types of fields. Forexample, many limit order events will have fields that vary based on thevalue of the AMD flag field 1918. As another example, some limit orderevents 1600 will not include a symbol field 1902. In such an instance,the symbol mapping task would be performed by the ONPA module 1208rather than the SM module 1206. As an example of such a circumstance, inorder to conserve bandwidth on data transmission links, several marketcenters minimize the size of event messages by sending “static”information regarding outstanding limit orders only once. Typically, thefirst message advertising the addition of a new limit order includes allassociated information (such as the symbol, source identifier, price andsize of the order, etc.) as well as a reference number for the order.Subsequent messages reporting modification or deletion of the order mayonly include a reference number that uniquely identifies the order (thusomitting a symbol field from the event). In a preferred embodiment, oneof the roles for the ONPA module 1208 is to pass complete orderinformation to downstream consumers of the event messages. For limitorder event messages, the ONPA module 1208 normalizes the messages byensuring that all desired fields are present in a regular format and themessage consistently communicates the market event. For example, amarket center may choose to advertise all events using ordermodification events. In such a scenario, with a preferred embodiment, itis the responsibility of the ONPA module 1208 to determine if the eventresults in the addition of a new order, modification of an existingorder, or deletion of an existing order. In practice, market centershave disparate data models for communicating limit order events; theONPA module 1208 ensures that a consistent data model is presented todownstream processing blocks and trading applications. All output eventscontain a consistent set of fields where each field has a well-definedtype. For example, some exchanges may only send the order referencenumber in a delete event. The ONPA module 1208 fills in missing fieldssuch as the price and size of the deleted order.

In order to resolve the symbol identifier for input events lacking asymbol field, the ONPA module 1208 can use another identifying field(such as an order reference number). In this case, the ONPA module 1208performs a many-to-one translation to resolve the symbol identifier, asthere may be many outstanding orders to buy or sell a given financialinstrument. It is important to note that this many-to-one mappingrequires maintaining a dynamic set of items that map to a given symbolidentifier, items may be added, modified, or removed from the set at anytime as orders enter and execute at market centers.

While there are several viable approaches to solve the ordernormalization problem, the preferred method is to maintain a record forevery outstanding limit order advertised by the set of input market datafeeds. An example of such a limit order record 2000 is shown in FIG. 20.An event reporting the creation of a new limit order must contain asymbol field, thus when the event arrives at the ONPA module 1208 itwill contain the symbol identifier resolved by the symbol mapping stage.If the event is from a market center that uses order reference numbersto minimize subsequent message sizes, the event will also contain anorder reference number. The ONPA module 1208 maintains a map to theorder record, where the record 2000 may contain the symbol identifier,order reference number, price, size, and other fields provided by themarket center. Preferably, the ONPA module 1208 also assigns a uniqueinternal order identifier 2002 that may be used to directly address theorder record by other system components.

In the example of FIG. 20, the limit order record 2000 comprises aplurality of fields, such as:

-   -   A unique internal identifier field 2002 as noted herein.    -   A symbol field 2004 as noted herein.    -   A GEID field 2006 as noted herein.    -   A reference number field 2008 as noted herein.    -   A bid/ask flag field 2010 as noted herein.    -   A price field 2012 as noted herein.    -   A size field 2014 as noted herein. As explained below, the value        of this field in the record 2000 may be updated over time as        order modify events are received.    -   A timestamp field 2016 as noted herein    -   A flag field 2018 for a first attribute (A0) (e.g., to identify        whether the order pertains to an ephemeral regional order)    -   A flag field for a second attribute (A1) (e.g., to identify        whether the order is an implied order. Together the A0 and A1        flags can be characterized as an order attribute vector 2030        within the limit order record 2000.    -   An interest vector field 2022 that serves to identify downstream        subscribers that have an interest in the subject limit order.        Optionally, this vector can be configured to not only identify        which subscribers are interested in which limit orders but also        what fields in each limit order record each subscriber has an        interest in.

Once again, however, it should be noted that limit order records 2000can be configured to have more or fewer and/or different data fields.

Preferably, the mapping of a received limit order event 1600 to a limitorder record 2000 is performed using hashing in order to achieveconstant time access performance on average. The hash key may beconstructed from the order reference number, symbol identifier, or otheruniquely identifying fields. The type of hash key is determined by thetype of market center data feed. Upstream feed handlers that performpre-normalization of the events set flags in the event that notify theONPA module as to what type of protocol the exchange uses and whatfields are available for constructing unique hash keys. For example,this information may be encoded in the GEID field 2006 or in some otherfield of the limit order event 1600. There are a variety of hashfunctions that could be used by the ONPA module. In the preferredembodiment, the ONPA employs H3 hash functions as discussed above and inthe above-referenced and incorporated U.S. Patent ApplicationPublication 2008/0243675 due to their efficiency and amenability toparallel hardware implementation. Hash collisions may be resolved in anumber of ways. In the preferred embodiment, collisions are resolved viachaining, creating a linked list of entries that map to the same hashslot. A linked list is a simple data structure that allows memory to bedynamically allocated as the number of entries in the set changes.

Once the record is located, the ONPA module updates fields in the recordand copies fields from the record to the message, filling in missingfields as necessary to normalize the output message. It is during thisstep that the ONPA module may modify the type of the message to beconsistent with the result of the market event. For example, if theinput message is a modify event that specifies that 100 shares should besubtracted from the order (due to a partial execution at the marketcenter) and the outstanding order is for 100 shares, then the ONPA willchange the type of the message to a delete event, subject to marketcenter rules. Note that market centers may dictate rules such as whetheror not zero size orders may remain on an order book. In anotherscenario, if the outstanding order was for 150 shares, the ONPA modulewould update the size field 2014 of the limit order record to replacethe 150 value with 50 reflect the removal of 100 shares from the order.In general, the ONPA module attempts to present the most descriptive andconsistent view of the market data events. Hardware logic within theONPA module can be configured to provide these updating andnormalization tasks.

In addition to normalizing order messages, the ONPA module mayadditionally perform price aggregation in order to support priceaggregated views of the order book. Preferably, the ONPA modulemaintains an independent set of price point records. In this datastructure, a record is maintained for each unique price point in anorder book. At minimum, the set of price point records preferablycontain the price, volume (sum of order sizes at that price, which canbe referred to as the price volume), and order count (total number oforders at that price). Order add events increase the volume and ordercount fields, order delete events decrease the volume and order countfields, etc. Price point records are created when an order event adds anew price point to the book. Likewise, price point records are deletedwhen on order event removes the only record with a given price pointfrom the book. Preferably, the ONPA module updates AMD flags in anenriched limit order event 1604 that specify if the event resulted inthe addition, modification, or deletion of a price entry in the book(see the price AMD field 2226 in FIG. 22). This information may be usedto optimize downstream sorting engines. Preferably, the ONPA module alsoassigns a unique internal price identifier to each price record that maybe used to directly address the price record by other system components.

Note that mapping a limit order event 1600 to a price point record isalso a many-to-one mapping problem. Preferably, the set of price pointrecords is maintained using a hash mapping, similar to the orderrecords. In order to locate the price point record associated with anorder event, the hash key is constructed from fields such as the symbolidentifier, global exchange identifier, and price. Preferably, hashcollisions are resolved using chaining as with the order record datastructure. Other data structures may be suitable for maintaining thesets of order and price point records, but hash maps have the favorableproperty of constant time accesses (on average).

In order to support efficient attribute filtering and price levelmerging in downstream book views, the ONPA module preferably maintains aprice attribute vector as part of the price point records, wherein theprice attribute vectors also comprise a vector of volumes and pricecounts in each price point record. For example, the price point recordmay include the following fields: price, volume (total shares or lots atthis price), order count (total orders at this price), attribute flags,attribute volume 0 (total shares or lots at this price with attribute0), order count 0 (total orders at this price with attribute 0),attribute volume 1, attribute order count 1, etc. Examples of such pricepoint records are shown in FIGS. 21( a) and (b). In general, the numberof unique attributes for a given financial instrument is expected to besmall. Preferably, the ONPA module is configurable to allow the numberof possible attributes to be defined dynamically for a given financialinstrument.

The ONPA module may append the volume, order count, and price attributeto events when creating enriched limit order events 1604. Preferably,the ONPA module maintains price interest vectors that specify if anydownstream applications or components require the price aggregatedand/or attribute information. Furthermore, the ONPA module preferablyupdates flags in the event that specify if the event resulted in theaddition, modification, or deletion of a price entry in the book asdefined by attribute (see the price AMD field 2226 in FIG. 22).

The data structure used to store price point records preferablyseparately maintains regional price point records 2100 and compositeprice point records 2150 for limit orders. A regional price point record2100 stores price point information for limit orders pertaining to afinancial instrument traded on a specific regional exchange. A compositeprice point record 2150 stores price point information for limits orderpertaining to a financial instrument traded across multiple exchanges.An example of a regional price point record is shown in FIG. 21( a), andan example of a composite price point record is shown in FIG. 21( b).

An exemplary regional price point record 2100 comprises a plurality offields, such as:

-   -   A unique internal (UI) regional price identifier field 2102 for        providing an internal identifier with respect to the subject        price point record.    -   A symbol field 2104 as noted herein.    -   A GEID field 2106 as noted herein.    -   A bid/ask flag field 2108 as noted herein.    -   A price field 2110 as noted herein.    -   A volume field 2112, which identifies the volume of shares        across all limit orders for the financial instrument (see the        symbol field 2104) on the regional exchange (see the GEID field        2106) at the price identified in the price field 2110.    -   A count field 2114, which comprises a count of how many limit        orders make up the volume 2112.    -   A timestamp field 2116 as noted above (which preferably is        representative of the timestamp 1914 for the most recent limit        order event 1600 that caused an update to the subject price        point record.    -   A regional price attribute vector 2140, which as noted above,        preferably not only flags whether any attributes are applicable        to at least a portion of the volume making up the subject price        point record, but also provides a breakdown of a volume and        count for each attribute. For example, a flag 2118 to indicate        whether attribute A0 is applicable, together with a volume 2120        and count 2122 for attribute A0, and a flag 2124 to indicate        whether attribute A1 is applicable, together with a volume 2126        and count 2128 for attribute A1.    -   An interest vector field 2130 that serves to identify downstream        subscribers that have an interest in the subject price point        record. Optionally, this vector can be configured to not only        identify which subscribers are interested in the regional price        point record but also what fields in each regional price point        record should each subscriber has an interest in.

An exemplary composite price point record 2150 comprises a plurality offields, such as:

-   -   A unique internal (UI) composite price identifier field 2152 for        providing an internal identifier with respect to the subject        price point record.    -   A symbol field 2154 as noted herein.    -   A bid/ask flag field 2156 as noted herein.    -   A price field 2158 as noted herein.    -   A volume field 2160, which essentially comprises the sum of the        volume fields 2112 for all regional price point records which        are aggregated together in the composite price point record.    -   A count field 2162, which essentially comprises the sum of the        count fields 2114 for all regional price point records which are        aggregated together in the composite price point record.    -   A timestamp field 2164 as noted above (which preferably is        representative of the timestamp 1914 for the most recent limit        order event 1600 that caused an update to the subject price        point record.    -   A composite price attribute vector 2180, which as noted above,        preferably not only flags whether any attributes are applicable        to at least a portion of the volume making up the subject price        point record, but also provides a breakdown of a volume and        count for each attribute. For example, a flag 2166 to indicate        whether attribute A0 is applicable, together with a volume 2168        and count 2170 for attribute A0, and a flag 2172 to indicate        whether attribute A1 is applicable, together with a volume 2174        and count 2176 for attribute A1.    -   An interest vector field 2178 that serves to identify downstream        subscribers that have an interest in the subject price point        record. Optionally, this vector can be configured to not only        identify which subscribers are interested in the composite price        point record but also what fields in each composite price point        record should each subscriber has an interest in.

Once again, however, it should be noted that regional and compositeprice point records 2100 and 2150 can be configured to have more orfewer and/or different data fields.

In the preferred embodiment, parallel engines update and maintain theorder and price aggregation data structures in parallel. In oneembodiment, the data structures are maintained in the same physicalmemory. In this case, the one or more order engines and one or moreprice engines interleave their accesses to memory, masking the memoryaccess latency of the memory technology and maximizing throughput of thesystem. There are a variety of well-known techniques for memoryinterleaving. In one embodiment, an engine controller block utilizes atime-slot approach where each engine is granted access to memory atregular intervals. In another embodiment, a memory arbitration blockschedules outstanding memory requests on the shared interface andnotifies engines when their requests are fulfilled. Preferably, thememory technology is a high-speed dynamic memory such as DDR3 SDRAM. Inanother embodiment, the order and price data structures are maintainedin separate physical memories. As in the single memory architecture,multiple engines may interleave their accesses to memory in order tomask memory access latency and maximize throughput.

FIG. 17 shows an example of how a single shared memory may bepartitioned to support order normalization, regional price aggregation,and composite price aggregation. In this example, each hash table isallocated a portion of the memory space. Hash collisions are resolved bychaining, creating a linked list of entries that map to the same hashslot. Linked list entries for all three hash tables are dynamicallyallocated from a common memory space. FIG. 18 shows an example of howthe ONPA module data structures may be partitioned across multiplephysical memories. In this particular example, the normalization datastructure is stored in one physical memory, while the regional andcomposite price aggregation data structures are stored in a secondphysical memory. This architecture allows memory accesses to beperformed in parallel.

The ONPA module 1208, upon receipt of a limit order event 1600, thus (1)processes data in the limit order event 1600 to access memory 1602(which may be multiple physical memories) and retrieve a limit orderrecord 2000, regional price point record 2100 and composite price pointrecord 2150 as appropriate, (2) processes data in the limit order eventand retrieved records to update the records as appropriate, and (3)enriches the limit order event 1600 with new information to create anenriched limit order event 1604. An example of such an enriched limitorder event 1604 is shown in FIG. 22. Preferably, the ONPA moduleappends a number of fields onto the limit order event 1600 that providedownstream subscribers with valuable information about market depth. Inthe example of FIG. 22, the enriched limit order event 1604 comprisesfields such as:

-   -   A field 2202 for the unique internal (UI) identifiers (such as        UI ID 2002, UI regional price ID 2102 and UI composite price ID        2152).    -   A symbol field 2204 as noted herein.    -   A GEID field 2206 as noted herein.    -   A reference number field 2208 as noted herein.    -   A bid/ask flag field 2210 as noted herein.    -   A price field 2212 as noted herein.    -   A size field 2214 as noted herein.    -   A timestamp field 2216 as noted herein.    -   A regional volume field 2218 and a regional count field 2220. It        should be noted that the ONPA module 1208 is preferably        configured to append these fields onto the limit order event        based on the updated volume and count values for the retrieved        regional price point record pertinent to that limit order event.    -   A composite volume field 2222 and a composite count field 2224.        It should be noted that the ONPA module 1208 is preferably        configured to append these fields onto the limit order event        based on the updated volume and count values for the retrieved        composite price point record pertinent to that limit order        event.    -   A field 2226 for identifying whether the limit order pertains to        an add, modify or delete (AMD) (a field that the ONPA module may        update based on the content of the limit order event relative to        its pertinent limit order record).    -   A price AMD field 2228 for identifying whether the limit order        event caused an addition, modification, or deletion from a        regional price point record and/or a composite price point        record. The ONPA module can append this field onto the limit        order event based on how the regional and composite price point        records were processed in response to the content of the        received limit order record 1600.    -   An enriched attribute vector 2250, which the ONPA module can        append to the limit order event as a consolidation of the        updated attribute vectors 2140 and 2180 for the regional and        composite price point records that are pertinent to the limit        order event. This enriched attribute vector can also include the        order attribute vector 2030 from the pertinent limit order        record. Thus, the enriched attributed vector 2250 may comprise        an order attribute vector field 2230, a regional price attribute        vector field 2232 and a composite price attribute vector field        2234.    -   An interest vector field 2236 that serves to identify downstream        subscribers that have an interest in data found in the enriched        limit order event. The ONPA module can append the interest        vector as a consolidation of the interest vectors 2022, 2130 and        2178 for the limit order, regional price point and composite        price point records that are pertinent to the limit order event.

Once again, however, it should be noted the ONPA module can beconfigured to enrich limit order events with more and fewer and/ordifferent data fields.

The outgoing enriched limit order events 1604 thus serve as the streamview of processed limit order data 1210 that can be produced by the ONPAmodule 1208 at extremely low latency.

A block diagram of an exemplary embodiment for the ONPA module 1208 isshown in FIG. 23.

The Extractor module is responsible for extracting from an input marketevent the fields needed by the rest of the modules within the ONPAmodule and presenting those fields in parallel to downstream modules.The Extractor also forwards the event to the Blender module for messagereconstruction.

The Price Normalizer module converts variably typed prices intonormalized fixed-sized prices (e.g. 64-bit values). In the preferredembodiment, the new prices are in units of either billionths or 256ths.The power of 2 price conversions may be performed by simple shifts. Thepower of 10 price conversions take place in a pipeline of shifts andadds.

In the preferred embodiment, the Hash modules are responsible for doingthe following:

-   -   Order Hash Module—Hashing the symbol, exchange identifier, and        order reference number to create an address offset into the        static order region of the memory which contains the first entry        in the linked list that contains or will contain the desired        order.    -   Price Hash Module—Hashing the symbol, exchange identifier, and        price to create an address offset into the static price region        of the memory (for both regional price records and composite        price records) which contains the first entry in the linked list        that contains or will contain the desired price level.    -   Header Hash Module—Hashing the symbol and the exchange        identifier to create an address offset into the static header        region that contains pointers to the first entries in both the        order refresh list and the price refresh list.

With respect to such refresh lists, the inventors note that a refreshevent can be used to initialize the book view provided to clientapplications. Thus, one of the responsibilities of the Level 2processing pipeline can be to generate book snapshots for clientapplication initialization. At subscription time, a refresh eventprovides a snapshot of the book at a particular instant in time. It isat this point that the appropriate bits in the interest vector are setin the appropriate data structures. Following the refresh event,incremental update events are delivered to the client application inorder to update the client application's view of the book. Refreshevents may be processed in-line with incremental update events in theFAM pipeline. In order to minimize the overhead of generating the booksnapshot, refresh events may be processed asynchronously. So long as thesnapshot of the book is an atomic event that records the event sequencenumber of the most recent update, the snapshot need not be processedsynchronous to all incremental update traffic. Synchronizing buffers inthe client API may be used to buffer incremental updates received priorto receipt of the refresh event. When the refresh event is received,incremental updates in the synchronization buffer are processed. Updateswith sequence numbers less than or equal to the sequence number noted inthe refresh event are discarded.

The Order Engine module is responsible for the following:

-   -   Traversing the hash linked list for limit order records.    -   Traversing the refresh linked lists for refreshes.    -   Performing adds, modifies, and deletes on the limit order        records.    -   Performing necessary maintenance to the linked lists.

The Price Engine module is responsible for the following:

-   -   Traversing the hash linked list for price levels in the regional        and composite price point records.    -   Traversing the refresh linked lists for refreshes.    -   Performing aggregation tasks for order adds, modifies, and        deletes at a given price level for the regional and composite        price point records.    -   Adding and deleting price levels as appropriate from the data        structure.    -   Performing necessary maintenance to the linked lists.

The Cache module optimizes performance by maintaining the most recentlyaccessed records in a fast, on-chip memory. The Cache module isresponsible for the following:

-   -   Storing limit order records, price point records, and header        nodes for fast and non-stale access.    -   Keeping track of which SDRAM addresses are cached.    -   Fetching un-cached data from SDRAM when requested by an order or        price engine.    -   Providing the local on-chip memory address for direct access        when an SDRAM address is queried.

The Operation FIFO module is responsible for the following:

-   -   Storing operation data during pipeline hibernation.    -   Monitoring next pointer information from the order and price        engines during deletes for automatic address forwarding.

The Refresh Queue module is configured to store refreshes that arereceived while another refresh is currently being processed. The Blendermodule may only able to check one order refresh and one price refresh ata time, which limits the number of concurrent refreshes. The SDRAMarbiter module arbitrates accesses from the order and price engines tothe two SDRAM interfaces. The Blender module also constructs an outgoingenriched and normalized event using the original event and variousfields created by the order and price engines (see FIG. 22). It alsocoalesces micro-events from refreshes to create outgoing requestedrefresh images. The Blender module is also preferably configured tonormalize conflicts between the refresh and the event stream.

If desired by a practitioner, the ONPA module's stream view output 1210,comprising the enriched limit order events, may be transmitted directlyto clients with appropriate stream view subscriptions. An Interest andEntitlement Filtering (IEF) module 1210 can be located downstream fromthe ONPA module as shown in FIGS. 12 (b) and (c). The IEF module 1210can be configured to utilize the mapped symbol index to resolve the setof interested and entitled clients for the given enriched limit orderevent, as described in the above-referenced and incorporated U.S. PatentApplication Publication 2008/0243675. Also, for enriched limit orderevents 1604 that include an interest vector field 2234, the IEF module1210 can also utilize such an interest vector to identify interested andentitled clients. The filtering aspect of the IEF module may be extendedto filter specific fields from enriched limit order events 1604 based onthe type of book view specified by client applications. For example, asorted order view does not require price aggregated volume and ordercount fields, and the IEF module 1210 can be configured to remove thosefields from enriched limit order events for clients who want a sortedorder view. Event transmission latency can be reduced and downstreamnetwork bandwidth can be conserved by omitting these fields from updateevents.

As shown in FIG. 12( c), a message formatting (MF) module 1212 can bedeployed downstream from the IEF module 1210 to format outgoing enrichedlimit order events destined for interested and entitled subscribers to amessage format expected by those subscribers. An exemplary embodimentfor the MF module 1212 is described in the above-referenced andincorporated U.S. Patent Application Publication 2008/0243675.

As noted above, some clients may prefer to receive a stream viewcomprising enriched limit order events because they will build their ownsorted data structures of the order book data. Thus, in one embodimentof the invention, the output of the pipeline 1200 shown in FIGS. 12(a)-(c) can be transmitted to a consuming system (client machine) whereit is processed by an Application Programming Interface (API) associatedwith the ticker plant, as shown in connection with FIG. 24. The APIperforms the sorting and presents the client application with a summaryview of the data. The sorting task may be performed using a variety oftechniques known in the art.

However, other clients may prefer to receive the summary view from theticker plant itself. For additional embodiments of the invention, theinventors disclose sorting techniques that can be deployed in pipeline1200 implemented within the ticker plant coprocessor to create summaryviews of the order data. However, it should be noted that these sortingtechniques could also be performed in an API as shown in FIG. 24 ifdesired by a practitioner.

FIGS. 25( a)-(d) depict exemplary embodiments of the pipeline 1200 wherea Sorted View Update (SVU) module 2500 is included to create a summaryview 2502 of the order books from the enriched limit order events. Withthe examples of FIGS. 25( b)-(d), it should be noted that the pipeline1200 is configured to provide both stream views 1210 to interest clientsand summary views 2402 to interest clients.

While the SVU module 2500 can be configured to provide sortingfunctionality via any of a number of techniques, with a preferredembodiment, the SVU module employs sorting engines to independentlymaintain each side (bid and ask) of each order book. Since input orderand price events only affect one side of the order book, accessing eachside of the book independently reduces the potential number of entriesthat must be accessed and provides for parallel access to the sides ofthe book. Each side of the book is maintained in sorted order inphysical memory. The book is “anchored” at the bottom of the memoryallocation for the book, i.e. the last entry is preferably always storedat the last address in the memory allocation. As a consequence thelocation of the “top” of the book (the first entry) varies as thecomposition of the order book changes. In order to locate the top of thebook, the SVU module 2500 maintains a record that contains pointers tothe top of the bid and ask side of the book, as well as other meta-datathat may describe the book. The record may be located directly by usingthe symbol map index. Note that inserting an entry into the book movesentries above the insertion location up one memory location. Deleting anentry in the book moves entries above the insertion location down onememory location. While these operations may result in large numbers ofmemory copies, performance is typically good as the vast majority oforder book transactions affect the top positions in the order book.Since the price AMD field 2226 in the enriched limit order event 1604specifies whether or not a price entry has been inserted or deleted, thesorting engine within the SVU module 2500 can make use of thisinformation to make a single pass through the sorted memory array.Furthermore, since the price aggregation engine within the ONPA modulemaintains all volume, order count, and attribute information for eachprice entry in the price point records, the entries in the SVU datastructure only need to store the values required for sorting.

For regional order summary views, the SVU module preferably maintains apair of bid and ask books for each symbol on each exchange upon which ittrades. The entries in each book are from one exchange. Since the orderengine within the ONPA module maintains all information associated withan order, the SVU data structure only needs to maintain the fieldsnecessary for sorting and the unique order identifier assigned by theONPA module. In some cases, only the price and timestamp are requiredfor sorting.

For price summary views, the SVU module preferably maintains a pair ofspliced bid and ask books for each symbol. The entries in each book arefrom every exchange upon which the symbol trades. Since the priceaggregation engine within the ONPA module maintains all informationassociated with a price level, the SVU data structure only needs tomaintain the fields necessary for sorting (i.e. price) and the uniqueprice identifier assigned by the ONPA module. Composite, spliced, andregional views of the price book may be synthesized from this singlespliced book. Attribute filtered and price merged views of the pricebook may be synthesized in the same way. A price book sorting engine inthe SVU module computes the desired views by aggregating multipleregional entries to produce composite entries and positions, and filtersunwanted regional price entries to produce regional entries andpositions. These computations are performed as the content of each bookis streamed from memory through the engine. In order to minimize thememory bandwidth consumed for each update event, the engine requestschunks of memory that are typically smaller in size than the entireorder book. Typically, a default memory chunk size is specified atsystem configuration time. Engines request the default chunk size inorder to fetch the top of the book. If additional book entries must beaccessed, the engines request the next memory chunk, picking up at thenext address relative to the end of the previous chunk. In order to maskthe latency of reading chunks of memory, processing, and requesting thenext chunk of memory, multiple engines interleave their accesses tomemory. As within the ONPA module, interleaving is accomplished by usinga memory arbitration block that schedules memory transactions formultiple engines. Note that a time-slot memory controller may also beused. Engines may operate on unique symbols in parallel withoutaffecting the correctness of the data.

In another embodiment of the Sorted View Update module, each side of thebook is organized as a hierarchical multi-way tree. The depth of amulti-way tree is dictated by the number of child branches leaving eachnode. A B+ tree is an example of a multi-way tree where all entries inthe tree are stored at the same level, i.e. the leaf level. Typically,the height of a multi-way tree is minimized in order to minimize thenumber of nodes that must be visited in order to reach a leaf node inthe tree, i.e. the desired entry. An example of a B+ tree is shown inFIG. 26. Note that the leaf nodes may be organized as a linked list suchthat the entire contents of the tree may be accessed by navigating tothe leftmost child and following the pointers to the next child node.This feature can be exploited in the SVU module to quickly produce arefresh event, a snapshot of the entire contents of the order book inorder to initialize newly subscribed clients. Furthermore, a directpointer to the leftmost child may be stored along with the root node inorder to provide fast access to the top of the sorted book.

FIG. 26 shows a simple example of a set of positive integers sortedusing a B+ tree. Note that all of the stored integers are stored in theleaf nodes. As is well-known in the art, B+ tree nodes vary in sizebetween a minimum and maximum size threshold that is dictated by thebranching factor of the tree. Note that “next pointers” are stored ineach leaf node to create a linked list of leaf nodes that may be quicklytraversed to retrieve the entire sorted order. Internal tree nodescontain integers that dictate ranges stored the child nodes. Forexample, all integers less than or equal to 7 are stored in the leftsub-tree of the root node.

The SVU module can be configured to utilize hierarchical B+ trees tominimize the number of memory accesses required to update the variousbook views. As shown in FIG. 27, the SVU module can be configured tomaintain a header record that contains pointers to the root of thecomposite and regional book trees. The root tree is the price aggregatedtree. Each leaf of the price aggregated tree contains a pointer to a B+tree that maintains a sort of the orders at the given price point. Withsuch an embodiment, the SVU module preferably maintains a hierarchicalB+ tree for the composite views and each regional view of the book. Notethat each side of the book (bid and ask) corresponds to a hierarchicalB+ tree. Note that hierarchical B+ trees may also be used in theembodiment where sorting is performed by the API on the client machine.Furthermore, note that a portion of the sorting may be offloaded to theAPI on the client machine. For example, construction of the spliced viewof the book may be offloaded to the API by subscribing to the summaryview of all regional books.

Similar to the insertion sorting engines in the previous embodiment, aparallel set of tree traversal engines can operate in parallel andinterleave their accesses to memory. Furthermore, the SVU module mayoptionally cache recently accessed tree nodes in on-chip memory in orderto further reduce memory read latency.

FIG. 28 depicts an exemplary embodiment for the SVU module 2500. Likethe ONPA module, the SVU module 2500 of FIG. 28 utilizes a functionalpipeline to achieve parallelism among the dispatching and sortingengines. It also uses data parallelism to instantiate multiple sortingengines in order to make full use of the available memory bandwidth tomaximize message throughput performance.

The Extractor module provides the same service of extracting necessaryfields for processing as described in connection with the ONPA module,and the Extractor module further propagates those fields to theDispatcher. The Extractor module also preferably propagates the fullevent to the Blender module.

The Dispatcher module is responsible for fetching the header record thatcontains pointers to the composite and regional book trees. A cachepositioned between the Dispatcher module and the SDRAM Arbiter moduleprovides quick access to recently accessed header records. The operationFIFO module stores event fields and operational state while theDispatcher module is waiting for memory operations to complete. Thisallows the Dispatcher module to operate on multiple events in parallel.

When the book pointers have been received from memory, the Dispatchermodule passes the event fields and the book pointers to one of severalparallel sorting engine modules. All events for a given symbol arepreferably processed by the same sorting engine module, but events fordifferent symbols may be processed in parallel by different sortingengine modules. The Dispatcher module may balance the workload acrossthe parallel sorting engines using a variety of techniques well-known inthe art. For example, the inventors have found that a randomdistribution of symbols across sorting engines provides an approximatelyeven load balance on average. Note that a Dispatch Buffer module residesbetween the Dispatcher module and the sorting engines. This buffermaintains separate queues of pending events for each sorting engine. Itreduces the probability of head-of-line blocking when a single sortingengine is backlogged. Pending events for that engine are buffered, whileevents scheduled for other sorting engines may be processed when theassociated sorting engine is ready. The sorting engine may utilize themodified insertion sort or B+ tree sorting data structures describedabove. In the preferred embodiment, the B+ tree sorting data structureis used. The sorting engine is responsible for:

-   -   Inserting and removing price levels from the sorted data        structure    -   Inserting and removing orders from sorted price levels in the        sorted listing    -   Identifying the relative position of the price level    -   Identifying the relative position of the order

The sorting engines include the relative price and order position inoutgoing events. For example, the sorting engines can be configured toappend data fields onto the order events it processes that identify thesort position for the order and/or price within the various booksmaintained by the data structure. Thus, the SVU module can create thesummary views by further enriching the limit order events that itreceives with sort position information for one or more books maintainedby the pipeline. This positional information may be in the form of ascalar position (e.g. 3^(rd) price level) or a pointer to the previousentry (e.g. pointer to the previous price level). Each sorting enginehas an associated cache, operation FIFO, and refresh FIFO. The cacheprovides fast access to recently accessed memory blocks, which optimizeslatency performance for back-to-back operations to the top of the sameorder book. Each sorting engine may operate on multiple events inparallel by storing in-process fields and state in its operation FIFO.Note that the sorting engines ensure correctness and data structurecoherency by monitoring for accesses to the same data structure nodes.Similarly, the sorting engines incrementally process refresh events toservice new client subscriptions by employing the refresh queue, similarto the ONPA module.

The output of each sorting engine is passed to the Blender module whichconstructs the normalized output event by blending the positionalinformation from the sorting engine with the event fields passed by theExtractor module. Note that the Blender maintains a queue for eachsorting engine that stores the pending event fields.

Level 2 updates from the ticker plant may be delivered to clientapplications in the form of discrete events that update the state of oneor more book views presented by the client API. For summary views, theAPI preferably maintains a mirror data structure to the SVU module. Forexample, if the SVU module employs B+ trees the API preferably maintainsa B+ tree. This allows the SVU module to include parent/child pointersin the update event. Specifically, the SVU module assigns a locallyunique identifier to each node in the B+ tree for the given book view.The SVU module enriches the update events with these identifiers tospecify the maintenance operations on affected nodes in the datastructure. For example, the update event may specify that the givenprice identifier be added to a given node. This allows the API toperform constant time updates to its data structure using directaddressing and prevents the need for a tree search operation.

Level 2 updates from the ticker plant may also be delivered to clientapplications in the form of snapshots of the top N levels of a bookview, where N is typically on the order of 10 or less. N may bespecified by the ticker plant or the subscribing application. In thecase that the book view is natively maintained by the SVU module, thesnapshot is readily produced by simply reading the first N entries inthe sorted data structure. When B+ trees are used, nodes may be sizedsuch that snapshots may be produced in a single memory read. In the casethat the SVU module synthesizes the book view (such as composite orattribute filtered views), the SVU preferably reads a sufficient numberof entries from the underlying sorted view to produce N entries in thesynthesized view. Snapshot delivery from the ticker plant significantlyreduces the amount of processing required on client systems by the APIto produce the specified book views. The API simply copies the snapshotinto a memory array and presents the view to the client application.

In accordance with another embodiment, the pipeline 1200 can leverageits likely ability to generate quote messages before that quote appearsin a Level 1 feed published by an exchange. As shown in FIG. 29, thepipeline 1200 can be augmented to pass synthetic quote events from theSVU module to a Value Cache Update (VCU) module 2900 that handles Level1 traffic. With the embodiment of FIG. 29, the SVU module is configuredwith logic for detecting when an order or price book update eventmodifies the top of the book (best bid or offer) (e.g., new price, size,or timestamp). In response to detecting such an event, the SVU modulegenerates a synthetic quote event that contains the new bid or ask priceand aggregate order size at that price for the given regional and/orcomposite view of the book for the associated symbol. The VCU module2900 receives this synthetic quote event, updates a Last Value Cache(LVC) data structure that contains the associated Level 1 record for thesymbol and transmits a Level 1 quote message to interested and entitledsubscribers. Records in the LVC data structure represent a current stateof a financial instrument in the market place. As indicated above,because of the extreme low latency provided by the ONPA and SVU modules,it is expected that the SVU module will be able to recognize when orderevents affect the top of a book before that situation is reflected in aconventional level 1 feed from an exchange. Thus, by recognizing anddelivering synthetic quote events to the VCU module 2900, the inventorsbelieve that the pipeline 1200 of FIG. 29 is configured to generatelevel 1 events from a feed of level 2 events with favorably low latency.

It should be noted that an exemplary embodiment for the VCU module 2900is described in the above-referenced and incorporated U.S. PatentApplication Publication 2008/0243675 (e.g., see FIGS. 15( a) and (b)therein).

In yet another exemplary embodiment, the pipeline 1200 of FIG. 29 can befurther configured to include a basket calculation engine (BCE) module3000 downstream from the VCU module 2900. An exemplary embodiment forthe BCE module 3000 is described in the above-referenced andincorporated U.S. Patent Application Publication 2009/0182683. The BCEmodule 3000 can be configured to operate on level 1 event resulting fromthe synthetic quote event to effectively drive Net Asset Value (NAV)computations for baskets of financial instruments from low latency Level2 data. The inventors believe that this chaining of synthetic quotegeneration and basket calculation is capable of providing a considerablespeed advantage for a number of trading strategies including indexarbitrage.

The aforementioned embodiments of the pipeline 1200 may be implementedin a variety of parallel processing technologies including: FieldProgrammable Gate Arrays (FPGAs), Chip Multi-Processors (CMPs),Application Specific Integrated Circuits (ASICs), Graphics ProcessingUnits (GPUs), and multi-core superscalar processors. Furthermore, suchpipelines 1200 may be deployed on coprocessor 840 of a ticker plantplatform 3100 as shown in FIG. 31. It should also be noted that thepipelines disclosed herein can be implemented not only in the tickerplants resident in trading firms but also in the ticker plants residentwithin the exchanges themselves to accelerate the exchanges' abilitiesto create and maintain their own order books. Additional detailsregarding such a ticker plant platform 3100 can be found in theabove-referenced and incorporated U.S. Patent Application Publications2009/0182683 and 2008/0243675. In summary, the financial market datafrom the exchanges is received at the O/S supplied protocol stack 3102executing in the kernel space on processor 812 (see FIGS. 8( a)-(b)). Anupject driver 3104 delivers this exchange data to multi-threaded feedpre-processing software 3112 executing in the user-space on processor812. These threads may then communicate data destined for thecoprocessor 840 to the hardware interface driver software 3106 runningin the kernel space.

Instructions from client applications may also be communicated to thehardware interface driver 3106 for ultimate delivery to coprocessor 840to appropriately configure pipeline 1200 that is instantiated oncoprocessor 840. Such instructions arrive at an O/S supplied protocolstack 3110 from which they are delivered to a request processingsoftware module 3116. A background and maintenance processing softwaremodule 3114 thereafter determines whether the client application has theappropriate entitlement to issue such instructions. If so entitled, thebackground and maintenance processing block 3114 communicates a commandinstruction to the hardware interface driver 3106 for delivery to thecoprocessor to appropriately update the pipeline 1200 to reflect anyappropriate instructions.

The hardware interface driver 3106 then can deliver an interleavedstream of financial market data and commands to the coprocessor 840 forconsumption thereby. Details regarding this stream transfer aredescribed in the above-referenced and incorporated U.S. PatentApplication Publication 2007/0174841. Outgoing data from the coprocessor840 returns to the hardware interface driver 3106, from which it can besupplied to MDC driver 3108 for delivery to the client connections (viaprotocol stack 3110) and/or delivery to the background and maintenanceprocessing block 3114.

While the present invention has been described above in relation to itspreferred embodiments, various modifications may be made thereto thatstill fall within the invention's scope. Such modifications to theinvention will be recognizable upon review of the teachings herein.Accordingly, the full scope of the present invention is to be definedsolely by the appended claims and their legal equivalents.

What is claimed is:
 1. An apparatus comprising: a ticker plant, theticker plant comprising a reconfigurable logic device, wherein thereconfigurable logic device is configured to synthesize quote eventsassociated with a plurality of financial instruments by (1) ingesting alevel 2 financial market data feed comprising a plurality of limit orderevents, the plurality of limit order events pertaining to a plurality offinancial instruments, (2) processing the limit order event data toupdate a plurality of order books, the order books pertaining to aplurality of financial instruments, (3) determining, in response to theprocessing, whether a limit order event modifies the top of an orderbook, and (4) generating synthesized quote event data for a limit orderevent determined to modify the top of an order book.
 2. The apparatus ofclaim 1 wherein the reconfigurable logic device is in communication witha last value cache (LVC) data structure, and wherein the reconfigurablelogic device is further configured to update the LVC data structurebased on the synthesized quote event data.
 3. The apparatus of claim 1wherein the reconfigurable logic device comprises a basket calculationengine (BCE) module, and wherein the reconfigurable logic device isfurther configured to provide the synthesized quote event data to theBCE module, and wherein the BCE module is configured to compute a newvalue for a financial instrument basket based on the synthesized quoteevent data.
 4. The apparatus of claim 3 wherein the BCE module isfurther configured to perform the computation by computing an updatednet asset value (NAV) for a financial instrument basket which has amember the financial instrument pertaining to the limit order event thatmodified the top of the order book.
 5. The apparatus of claim 3 whereinthe reconfigurable logic device comprises a field programmable gatearray (FPGA).
 6. The apparatus of claim 1 wherein the reconfigurablelogic device is further configured to modify the order books based onthe processed limit order event data.
 7. The apparatus of claim 1wherein the reconfigurable logic device comprises a field programmablegate array (FPGA).
 8. A method comprising: synthesizing quote eventsassociated with a plurality of financial instruments from a level 2financial market data feed using a reconfigurable logic device within aticker plant; wherein the synthesizing step comprises the reconfigurablelogic device (1) ingesting a level 2 financial market data feedcomprising a plurality of limit order events, the plurality of limitorder events pertaining to a plurality of financial instruments, (2)processing the limit order event data to update a plurality of orderbooks, the order books pertaining to a plurality of financialinstruments, (3) determining, in response to the processing, whether alimit order event modifies the top of an order book, and (4) generatingsynthesized quote event data for a limit order event determined tomodify the top of an order book.
 9. The method of claim 8 furthercomprising: the reconfigurable logic device updating a last value cache(LVC) data structure based on the synthesized quote event data.
 10. Themethod of claim 8 further comprising: providing the synthesized quoteevent data to a basket calculation engine deployed on the reconfigurablelogic device; and the basket calculation engine computing a new valuefor a financial instrument basket based on the synthesized quote eventdata.
 11. The method of claim 10 wherein the computing step comprisesthe basket calculation engine computing an updated net asset value (NAV)for a financial instrument basket which has a member the financialinstrument pertaining to the limit order event that modified the top ofthe order book.
 12. The method of claim 10 wherein the reconfigurablelogic device comprises a field programmable gate array (FPGA).
 13. Themethod of claim 8 further comprising: the reconfigurable logic devicemodifying the order books based on the processed limit order event data.14. The method of claim 8 wherein the reconfigurable logic devicecomprises a field programmable gate array (FPGA).